The present proposal is for the further development and improvement of a multiple beam ultrasound Doppler flowmeter and electronic sector scan image for the early detection and quantitative evaluation of atherosclerosis. The present proposal is for the further development and improvement of the working prototype including completion of certain subsystems, evaluation of alternative transducer array designs, additional dog and model studies to evaluate the effectiveness of the prototype in measuring flow velocity, volume flow and flow turbulence, and additional clinical testing.